Commit Graph

1218 Commits

Author SHA1 Message Date
Peter Krempa
37e663adb6 virsh: Reject negative numbers in vshCommandOptUInt
Use virStrToLong_uip instead of virStrToLong_ui to reject negative
numbers in the helper. None of the callers expects the wraparound
"feature" for negative numbers.

Also add a function that allows wrapping of negative numbers as it might
be used in the future and be explicit about the new semantics in the
function docs.
2014-06-12 14:06:20 +02:00
Roman Bogorodskiy
aec0c6d3d5 virsh: include bhyve in virsh -V output
Add 'Bhyve' in hypervisor list reported by 'virsh -V'
if it's compiled it.
2014-06-11 22:16:09 +04:00
Chen Fan
c85b09cd7a virsh: Add details about specified migration host
the 'migration_host' description may be a bit difficult to
understand for some users, so enhance the manual

Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-10 11:20:06 -06:00
Eric Blake
b298025063 blockcommit: document semantics of committing active layer
Now that qemu 2.0 allows commit of the active layer, people are
attempting to use virsh blockcommit and getting into a stuck
state, because libvirt is unprepared to handle the two-phase
commit required by qemu.

Stepping back a bit, there are two valid semantics for a
commit operation:

1. Maintain a 'golden' base, and a transient overlay. Make
changes in the overlay, and if everything appears to work,
commit those changes into the base, but still keep the overlay
for the next round of changes; repeat the cycle as desired.

2. Create an external snapshot, then back up the stable state
in the backing file. Once the backup is complete, commit the
overlay back into the base, and delete the temporary snapshot.

Since qemu doesn't know up front which of the two styles is
preferred, a block commit of the active layer merely gets
the job into a synchronized state, and sends an event; then
the user must either cancel (case 1) or complete (case 2),
where qemu then sends a second event that actually ends the
job.  However, until commit e6bcbcd, libvirt was blindly
assuming the semantics that apply to a commit of an
intermediate image, where there is only one sane conclusion
(the job automatically ends with fewer elements in the chain);
and getting stuck because it wasn't prepared for qemu to enter
a second phase of the job.

This patch adds a flag to the libvirt API that a user MUST
supply in order to acknowledge that they will be using two-phase
semantics.  It might be possible to have a mode where if the
flag is omitted, we automatically do the case 2 semantics on
the user's behalf; but before that happens, I must do additional
patches to track the fact that we are doing an active commit
in the domain XML.  Later patches will add support of the flag,
and once 2-phase semantics are working, we can then decide
whether to relax things to allow an omitted flag to cause an
automatic pivot.

* include/libvirt/libvirt.h.in (VIR_DOMAIN_BLOCK_COMMIT_ACTIVE)
(VIR_DOMAIN_BLOCK_JOB_TYPE_ACTIVE_COMMIT): New enums.
* src/libvirt.c (virDomainBlockCommit): Document two-phase job
when committing active layer, through new flag.
(virDomainBlockJobAbort): Document that pivot also occurs after
active commit.
* tools/virsh-domain.c (vshDomainBlockJob): Cover new job.
* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Explicitly
reject active copy; later patches will add it in.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-10 11:11:16 -06:00
Ján Tomko
a3173fef9d Implement pretty flag for vcpuinfo and nodecpumap
Report CPU affinities / online CPUs in human-readable form when
this flag is present:

Before:
CPU Affinity:   y-yy

After:
CPU Affinity:   0,2-3 (out of 4)

https://bugzilla.redhat.com/show_bug.cgi?id=985980
2014-06-06 14:35:19 +02:00
Ján Tomko
8f3f51b723 virsh: Separate API calls and result printing in cmdVcpuinfo
This allows reuse of the result printing code.
2014-06-06 14:35:18 +02:00
Ján Tomko
bec105e6db virsh: Invert logic in cmdVcpuinfo
Initialize 'ret' to false and introduce a cleanup label.
2014-06-06 14:35:18 +02:00
Michal Privoznik
289a3163de virsh-nodedev: Avoid spurious errors
Our public free functions explicitly don't accept NULL pointers
(sigh). Therefore, callers must do something like this:

    if (dev)
        virNodeDeviceFree(dev);

And we are not doing that on two places I've found. This leads to
dummy error message thrown by virsh:

    virsh # nodedev-dumpxml nonexistent-device
    error: Could not find matching device 'nonexistent-device'
    error: invalid node device pointer in virNodeDeviceFree

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-02 18:09:09 +02:00
Peter Krempa
6ef0b03483 virsh: Check whether found volume is member of the specified storage pool
When looking up storage volumes virsh uses multiple lookup steps. Some
of the steps don't require a pool name specified. This resulted into a
possibility that a volume would be part of a different pool than the
user specified:

Let's have a /var/lib/libvirt/images/test.qcow image in the 'default'
pool and a second pool 'emptypool':

Currently we'd return:
  $ virsh vol-info --pool emptypool /var/lib/libvirt/images/test.qcow
  Name:           test.qcow
  Type:           file
  Capacity:       100.00 MiB
  Allocation:     212.00 KiB

After the fix:
 $ tools/virsh vol-info --pool emptypool /var/lib/libvirt/images/test.qcow
 error: Requested volume '/var/lib/libvirt/images/test.qcow' is not in pool 'emptypool'

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1088667
2014-06-02 10:56:49 +02:00
Eric Blake
be673413a3 virsh: fix typos in virsh man page
* tools/virsh.pod (attach-disk): Drop duplicate --config, fix typo
in --sourcetype.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-05-28 20:10:38 -06:00
Eric Blake
88b5acb67f build: nuke more uses of 'sync'
Commit d5c86278 was incomplete; other functions also triggered
compiler warnings about collisions in the use of 'sync'.

* src/qemu/qemu_driver.c (qemuDomainSetTime): Fix another client.
* tools/virsh-domain-monitor.c (cmdDomTime): Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-05-19 17:07:47 -06:00
Eric Blake
ab5178188f maint: shorten 'TypeType' function names
The VIR_ENUM_DECL/VIR_ENUM_IMPL helper macros already append 'Type'
to the enum name being converted; it looks silly to have functions
with 'TypeType' in their name.  Even though some of our enums have
to have a 'Type' suffix, the corresponding string conversion
functions do not.

* src/conf/secret_conf.h (VIR_ENUM_DECL): Rename virSecretUsageType.
* src/conf/storage_conf.h (VIR_ENUM_DECL): Rename
virStoragePoolAuthType, virStoragePoolSourceAdapterType,
virStoragePartedFsType.
* src/conf/domain_conf.c (virDomainDiskDefParseXML)
(virDomainFSDefParseXML, virDomainFSDefFormat): Update callers.
* src/conf/secret_conf.c (virSecretDefParseUsage)
(virSecretDefFormatUsage): Likewise.
* src/conf/storage_conf.c (virStoragePoolDefParseAuth)
(virStoragePoolDefParseSource, virStoragePoolSourceFormat):
Likewise.
* src/lxc/lxc_controller.c (virLXCControllerSetupLoopDevices):
Likewise.
* src/storage/storage_backend_disk.c
(virStorageBackendDiskPartFormat): Likewise.
* src/util/virstorageencryption.c (virStorageEncryptionSecretParse)
(virStorageEncryptionSecretFormat): Likewise.
* tools/virsh-secret.c (cmdSecretList): Likewise.
* src/libvirt_private.syms (secret_conf.h, storage_conf.h): Export
corrected names.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-05-16 00:22:18 -06:00
Michal Privoznik
222fdbfd2b virsh: Expose virDomain{Get,Set}Time
These APIs are exposed under new virsh command 'domtime' which both gets
and sets (not at the same time of course :)).

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-05-15 16:44:38 +02:00
Li Yang
ed5950909d virsh: reject undefine --wipe-storage without also naming storage
For now, if only '--wipe-storage' is assigned, user can undefine a
domain normally. But actually '--wipe-storage' doesn't do anything,
and this may confuse user. Better is to require that '--wipe-storage'
only works if the user specifies volumes to be removed.

Before:
$ virsh undefine virt-tests-vm1 --wipe-storage
Domain virt-tests-vm1 has been undefined

After:
$ virsh undefine virt-tests-vm1 --wipe-storage
error: '--wipe-storage' requires '--storage <string>' or '--remove-all-storage'

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2014-05-14 11:11:50 -06:00
Julio Faracco
1ce86e62e1 conf: use typedefs for enums in "src/conf/storage_conf.h"
In "src/conf/" there are many enumeration (enum) declarations.
Similar to the recent cleanup to "src/util" directory, it's
better to use a typedef for variable types, function types and
other usages. Other enumeration and folders will be changed to
typedef's in the future. Most of the files changed in this
commit are related to storage (storage_conf) enums.

Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2014-05-14 10:18:35 -06:00
Peter Krempa
31b140eba4 virsh: domain: Fix output of the VNC display number for domdisplay
Commit 9976c4b9a6 broke the output for VNC
displays as the port number is converted to VNC display number by
subtracting 5900. This yields port 0 for the first display and thus the
output would be skipped.

Before:
 $ virsh domdisplay VM
 vnc://localhost

After:
 $ tools/virsh domdisplay VM
 vnc://localhost:0
2014-05-13 11:34:38 +02:00
Tomoki Sekiyama
061c6347e4 virsh: Expose new virDomainFSFreeze and virDomainFSThaw API
These are exposed under domfsfreeze command and domfsthaw command.

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
2014-05-12 21:01:13 -06:00
Li Yang
e4fe06e017 virsh: Replace list element to defined variable
Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
2014-05-05 13:49:09 -06:00
Jim Fehlig
b98bf81151 Introduce a new flag for controlling shutdown/reboot
Add a new flag to virDomain{Reboot,Shutdown}FlagValues to allow
shutting down and rebooting a domain via the Xen paravirt control
interface.
2014-05-05 10:52:21 -06:00
Daniel P. Berrange
391ac4d990 Activate build dir overrides in libvirtd, virtlockd, virsh & tests
Add calls to virFileActivateDirOverride so that the build dir
overrides are activated.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-04-25 11:59:32 +01:00
Ján Tomko
22a92eb0a7 Document behavior of setvcpus during guest boot
Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1088748

The hotplugged vcpus could fail to show up in the guest if
they were added during boot, see:
https://bugzilla.redhat.com/show_bug.cgi?id=807508

Also change arbitrary to arbitrarily.
2014-04-23 14:24:21 +02:00
Nehal J Wani
3d5c29a17c Fix typos in src/*
Fix minor typos in source comments

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-04-21 16:49:08 -06:00
Li Yang
00b1cce0c0 virsh: Fix comment of vshCmdInfo
The original comment of vshCmdInfo:
"name" - command name

Actually it's 'help' and the short description
of command, not the command name.

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
2014-04-09 16:29:58 +02:00
Guido Günther
5a05865773 libvirt-guests: avoid bashism
At least Debian uses dash to run the init scripts
2014-04-07 12:51:05 +02:00
Li Yang
cc7e150359 virsh: Make 'exit' action same as 'quit'
For now 'virsh quit' action like this:
--------------------------------
[root@localhost /]# virsh quit
[root@localhost /]#
--------------------------------
And 'virsh exit' action:
--------------------------------
[root@localhost /]# virsh exit

[root@localhost /]#
--------------------------------
There is a small difference('/n') between them.
According to manual said:
       quit, exit
           quit this interactive terminal

And in the code they all called cmdQuit func,
They should get same actions.

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
2014-04-03 11:57:53 +02:00
Shanzhi Yu
34a4316308 virsh: man: delete the unexpected character in snapshot-list 2014-04-02 13:00:00 +02:00
Eric Blake
8a20e227f6 conf: move storage source type to util/
With this patch, all information related to a host resource in
a storage file backing chain now lives in util/virstoragefile.h.
The next step will be to consolidate various places that have
been tracking backing chain details to all use a common struct.

The changes to tools/Makefile.am were made necessary by the
fact that virstorageencryption includes uses of libxml, and is
now pulled in by inclusion from virstoragefile.h.  No
additional libraries are linked into the final image, and in
comparison, the build of the setuid library in src/Makefile.am
already was using LIBXML_CFLAGS via AM_CFLAGS.

* src/conf/domain_conf.h (virDomainDiskSourceDef): Move...
* src/util/virstoragefile.h (virStorageSource): ...and rename.
* src/conf/domain_conf.c (virDomainDiskSourceDefClear)
(virDomainDiskAuthClear): Adjust clients.
* tools/Makefile.am (virt_login_shell_CFLAGS)
(virt_host_validate_CFLAGS): Add libxml headers.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-04-01 10:38:14 -06:00
Eric Blake
14d7fcc23a virsh: fix 'help event'
'virsh help event' included a summary line "event - (null)"
due to a misnamed info field.

* tools/virsh-domain.c (info_event): Use correct name.
* tools/virsh-network.c (info_network_event): Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-03-31 08:37:39 -06:00
Shanzhi Yu
bfd2f54cf2 virsh: man: Fix spelling of parameters for --memspec in snapshot-create-as
https://bugzilla.redhat.com/show_bug.cgi?id=1080859

Snapshot type should be no, internal, or external.
2014-03-31 14:06:41 +02:00
Li Yang
09bfe11090 Modify help information of virsh list command
Use 'virsh list domain --title' option can get domain's title,
not description, the original help information 'show short
domain description' will confuse users, so modify it to
'show domain title'

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
2014-03-27 06:58:46 -06:00
Ján Tomko
5d8793eebb Indent top-level labels by one space in tools/ 2014-03-25 14:58:41 +01:00
Qiao Nuohan
2f934550b9 allow "virsh dump --memory-only" specify dump format
This patch adds "[--format] <string>" to "virsh dump --memory-only", which is
changed to use the new virDomainCoreDumpWithFormat API.

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2014-03-24 14:14:14 -06:00
Chegu Vinod
05e1b06ab7 libvirt support to force convergence of live guest migration
Busy enterprise workloads hosted on large sized VM's tend to dirty
memory faster than the transfer rate achieved via live guest migration.
Despite some good recent improvements (& using dedicated 10Gig NICs
between hosts) the live migration may NOT converge.

Recently support was added in qemu (version 1.6) to allow a user to
choose if they wish to force convergence of their migration via a
new migration capability : "auto-converge". This feature allows for qemu
to auto-detect lack of convergence and trigger a throttle-down of the
VCPUs.

This patch includes the libvirt support needed to trigger this
feature. (Testing is in progress)

Signed-off-by:  Chegu Vinod <chegu_vinod@hp.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
2014-03-21 14:17:15 +01:00
Eric Blake
43b17dd444 qemu: allow filtering events by regex
When listening for a subset of monitor events, it can be tedious
to register for each event name in series; nicer is to register
for multiple events in one go.  Implement a flag to use regex
interpretation of the event filter.

While at it, prove how much I hate the shift key, by adding a
way to filter for 'shutdown' instead of 'SHUTDOWN'. :)

* include/libvirt/libvirt-qemu.h
(virConnectDomainQemuMonitorEventRegisterFlags): New enum.
* src/libvirt-qemu.c (virConnectDomainQemuMonitorEventRegister):
Document flags.
* tools/virsh-domain.c (cmdQemuMonitorEvent): Expose them.
* tools/virsh.pod (qemu-monitor-event): Document this.
* src/conf/domain_event.c
(virDomainQemuMonitorEventStateRegisterID): Add flags.
(virDomainQemuMonitorEventFilter): Handle regex, and optimize
client side.
(virDomainQemuMonitorEventCleanup): Clean up regex.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-03-20 11:25:37 -06:00
Eric Blake
88996de1c3 qemu: virsh wrapper for qemu events
Any new API deserves a good virsh wrapper :)

    qemu-monitor-event [<domain>] [<event>] [--pretty] [--loop] [--timeout <number>]

Very similar to the previous work on 'virsh event'.  For an
example session:

$ virsh -c qemu:///system qemu-monitor-event --event SHUTDOWN&
$ virsh -c qemu:///system start f18-live
Domain f18-live started

$ virsh -c qemu:///system destroy f18-live
Domain f18-live destroyed

event SHUTDOWN at 1391212552.026544 for domain f18-live: (null)
events received: 1

[1]+  Done                    virsh -c qemu:///system qemu-monitor-event --event SHUTDOWN
$

* tools/virsh-domain.c (cmdQemuMonitorEvent): New command.
* tools/virsh.pod (qemu-monitor-event): Document it.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-03-20 11:25:37 -06:00
Michal Privoznik
962abaf538 domiftune: Reword bandwidth clearing paragraph
s/of value/value of/

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-03-19 16:20:18 +01:00
Daniel P. Berrange
2835c1e730 Add virLogSource variables to all source files
Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-03-18 14:29:22 +00:00
Michal Privoznik
149733821d qemuDomainSetInterfaceParameters: Allow bandwidth clear out
We allow translation from no_bandwidth to has_bandwidth for a vnic.
However, going in the opposite direction is not implemented. It's not
limitation of the API rather than internal implementation. The problem
is, we correctly detect that user hasn't specified any outbound (say
he wants to clear out outbound). However, this gets overwritten by
current vnic outbound settings. Then, virNetDevBandwidthSet doesn't
change anything. We need to stop overwriting the outbound if users
don't want us to. Same applies for inbound.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-03-18 14:45:09 +01:00
Martin Kletzander
cc9c62fef9 Require spaces around equality comparisons
Commit a1cbe4b5 added a check for spaces around assignments and this
patch extends it to checks for spaces around '=='.  One exception is
virAssertCmpInt where comma after '==' is acceptable (since it is a
macro and '==' is its argument).

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-03-18 11:29:44 +01:00
Martin Kletzander
676cb4f4e7 virsh: Add keepalive in new vshConnect function
Introducing keepalive similarly to Guannan around 2 years ago.  Since
we want to introduce keepalive for every connection, it makes sense to
wrap the connecting function into new virsh one that can deal
keepalive as well.

Function vshConnect() is now used for connecting and keepalive added
in that function (if possible) helps preventing long waits e.g. while
nework goes down during migration.

This patch also adds the options for keepalive tuning into virsh and
fails connecting only when keepalives are explicitly requested and
cannot be set (whether it is due to missing support in connected
driver or remote server).  If not explicitely requested, a debug
message is printed (hence the addition to virsh-optparse test).

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1073506
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=822839

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-03-18 08:27:29 +01:00
Laine Stump
64bb902451 virsh: eliminate hardcoded indentation in xml generated for commands
These are never seen externally, only passed into libvirt APIs, so in
practice this makes no real difference, but it's good to be
consistent.
2014-03-14 00:02:38 -06:00
Ján Tomko
9b9d7704b5 Change file names in comments to match the files they are in
Some of these are leftovers from renaming the files, others
are just typos.

Also introduce an ugly awk script to enforce this.
2014-03-10 14:26:04 +01:00
Roman Bogorodskiy
356bf55e98 Fix locking in virsh console
vshRunConsole() uses virCondWait() which is a wrapper around
pthread_cond_wait(). On FreeBSD, pthread_cond_wait needs mutex to be
locked, otherwise it immediately fails with EPERM. On Linux, the
behaviour in this case is undefined.

So lock the mutex before calling virCondWait().
2014-03-10 14:51:32 +04:00
Martin Kletzander
fb235130fe virsh: Sort options alphabetically
Man page, help output and also parsing is sorted in order to find
options smoothly.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-03-10 10:50:06 +01:00
Eric Blake
cb9bd7963b virt-login-shell: silence coverity warning
Coverity spotted that 'nfdlist' (ssize_t) could be -1, but that we
were using 'i' (size_t) to iterate over the list at cleanup, with
crashing results because it promotes to a really big unsigned number.

* tools/virt-login-shell.c (main): Avoid treating -1 as unsigned.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-03-05 11:59:06 -07:00
Peter Krempa
a751e3452b virsh: volume: Fix lookup of volumes to provide better error messages
If a user specifies the pool explicitly, we should make sure to point
out that it's inactive instead of falling back to lookup by key/path and
failing at the end. Also if the pool isn't found there's no use in
continuing the lookup.

This changes the error in case the user-selected pool is inactive from:

 $ virsh vol-upload --pool inactivepool --vol somevolname volcontents
 error: failed to get vol 'somevolname'
 error: Storage volume not found: no storage vol with matching path
 somevolname

To a more descriptive:

 $ virsh vol-upload --pool inactivepool --vol somevolname volcontents
 error: pool 'inactivepool' is not active

And in case a user specifies an invalid pool from:

 $ virsh vol-upload --pool invalidpool --vol somevolname volcontents
 error: failed to get pool 'invalidpool'
 error: failed to get vol 'somevolname', specifying --pool might help
 error: Storage volume not found: no storage vol with matching path somevolname

To something less confusing:

 $ virsh vol-upload --pool invalidpool --vol somevolname volcontents
 error: failed to get pool 'invalidpool'
 error: Storage pool not found: no storage pool with matching name 'invalidpool'
2014-03-05 09:08:32 +01:00
Eric Blake
2ebf593a05 virsh: report exit status of failed lxc-enter-namespace
'virsh lxc-enter-namespace' does not have a way to reflect exit
status to the caller in single-command mode, but we might as well
at least report the exit status.  Prior to this patch,

$ virsh -c lxc:/// lxc-enter-namespace shell /bin/sh 'exit 3'; echo $?
1

now it gives some details:

$ virsh -c lxc:/// lxc-enter-namespace shell /bin/sh -c 'exit 3'; echo $?
error: internal error: Child process (31557) unexpected exit status 3
1

Also useful:

$ virsh -c lxc:/// lxc-enter-namespace shell /bin/sh -c 'kill $$'; echo $?
error: internal error: Child process (31585) unexpected fatal signal 15
1

* tools/virsh-domain.c (cmdLxcEnterNamespace): Avoid magic numbers.
Dispatch any error.
* tools/virsh.pod: Document that non-zero exit status is collapsed.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-03-03 12:40:32 -07:00
Eric Blake
730fc9622b virt-login-shell: saner exit value
virt-login-shell was exiting with status 0, regardless of what the
wrapped shell returned.  This is unkind to users; we should behave
more like env(1), nice(1), su(1), and other wrapper programs, by
preserving the invoked application's status (which includes the
distinction between death due to signal vs. normal death).

* tools/virt-login-shell.c (main): Pass through child exit status.
* tools/virt-login-shell.pod: Document exit status.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-03-03 12:40:32 -07:00
Eric Blake
4594a33b4b virt-login-shell: use single instead of double fork
Note that 'virsh lxc-enter-namespace' must double-fork, for two
reasons: some namespaces can only be done from a single thread,
while virsh is multithreaded; and because virsh can be run in
batch mode where we must not corrupt the namespace of that
execution upon return from the subsidiary command.

When virt-login-shell was first written, it blindly copied from
'virsh lxc-enter-namespace', including the double-fork.  But
neither of the reasons for double forking apply to
virt-login-shell (we are single-threaded, and we have nothing to
do after the child completes that would require us to preserve a
namespace), so we can simplify life by using a single fork.
In turn, this will make it easier for a future patch to pass the
child's exit status on to the invoking shell.

In flattening to a single fork, note that closing the fds must
be done after fork, because the parent process still needs to
use fds to control the virConnectPtr; meanwhile, chdir can be
done prior to forking (in fact, it's easier to report errors
on anything attempted before forking).

* tools/virt-login-shell.c (main): Single rather than double fork.
(virLoginShellFini): Delete, by inlining actions instead.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-03-03 12:40:32 -07:00
Eric Blake
25f87817ab virFork: simplify semantics
The old semantics of virFork() violates the priciple of good
usability: it requires the caller to check the pid argument
after use, *even when virFork returned -1*, in order to properly
abort a child process that failed setup done immediately after
fork() - that is, the caller must call _exit() in the child.
While uses in virfile.c did this correctly, uses in 'virsh
lxc-enter-namespace' and 'virt-login-shell' would happily return
from the calling function in both the child and the parent,
leading to very confusing results. [Thankfully, I found the
problem by inspection, and can't actually trigger the double
return on error without an LD_PRELOAD library.]

It is much better if the semantics of virFork are impossible
to abuse.  Looking at virFork(), the parent could only ever
return -1 with a non-negative pid if it misused pthread_sigmask,
but this never happens.  Up until this patch series, the child
could return -1 with non-negative pid if it fails to set up
signals correctly, but we recently fixed that to make the child
call _exit() at that point instead of forcing the caller to do
it.  Thus, the return value and contents of the pid argument are
now redundant (a -1 return now happens only for failure to fork,
a child 0 return only happens for a successful 0 pid, and a
parent 0 return only happens for a successful non-zero pid),
so we might as well return the pid directly rather than an
integer of whether it succeeded or failed; this is also good
from the interface design perspective as users are already
familiar with fork() semantics.

One last change in this patch: before returning the pid directly,
I found cases where using virProcessWait unconditionally on a
cleanup path of a virFork's -1 pid return would be nicer if there
were a way to avoid it overwriting an earlier message.  While
such paths are a bit harder to come by with my change to a direct
pid return, I decided to keep the virProcessWait change in this
patch.

* src/util/vircommand.h (virFork): Change signature.
* src/util/vircommand.c (virFork): Guarantee that child will only
return on success, to simplify callers.  Return pid rather than
status, now that the situations are always the same.
(virExec): Adjust caller, also avoid open-coding process death.
* src/util/virprocess.c (virProcessWait): Tweak semantics when pid
is -1.
(virProcessRunInMountNamespace): Adjust caller.
* src/util/virfile.c (virFileAccessibleAs, virFileOpenForked)
(virDirCreate): Likewise.
* tools/virt-login-shell.c (main): Likewise.
* tools/virsh-domain.c (cmdLxcEnterNamespace): Likewise.
* tests/commandtest.c (test23): Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-03-03 12:40:32 -07:00